Hookworm Life Cycle

Introduction

Hookworms are a type of parasitic nematodes that are inhabitants of the small intestine, skin and lungs of mammals like humans, dogs, and cats. Hookworms belong to the class Secernentea and the order Strongylida and the family Ancylostomatidae. Hookworm larvae and adults living in the small intestine can result in helminthiases, an intestinal ailment.

Ancylostoma duodenale and Necator americanus are the two main hookworm species that affect people. A. brasilense and A. caninum are the two canine hookworms that can infect people. In tropical and subtropical areas of the world, Necator americanus is the causative agent of nearly 90% of human hookworm infections.

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Features of Hookworm

• Hookworms can be identified by the presence of well-defined buccal capsules including teeth and clotting plates.

• A hookworm can grow up to 11 mm in length as an adult.

• A man's small intestine contains the adult worm primarily in the jejunum, less frequently in the duodenum, and infrequently in the ileum.

• Humans contract hookworms by eating contaminated food with hookworm larvae that are found in the faeces-contaminated ground or they enter the body through the bare feet when we come in contact with the worm dwelling in polluted soil.

• As per the reports of the Centers for Disease Control and Prevention, 576 to 740 million people globally are thought to be affected by hookworm infections due to insufficient access to clean water, sanitary facilities, and hygienic practices.

• The old hookworm, commonly known as Ancylostoma duodenale, is a typical human hookworm, that causes ancylostomiasis in people, which is characterised by hypoalbuminemia and non-deficiency anaemia.

• Another source of hookworm disease in humans is Necator americanus, sometimes referred to as the New World hookworm, which causes necatoriasis.

• The ideal temperature range for larval growth is between 70-85 degrees Fahrenheit, and A. duodenale is better adapted to the lower range of temperature than N. americanus, which is more common in temperate conditions.

• The intestinal hookworm species A. ceylanicum is currently one of the most common to infect humans worldwide.

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Life Cycle of Hookworm

The two species of hookworm Ancylostoma duodenale and Necator americanus have the same life cycle. The whole process occurs in one host, the human. No additional intermediary host is necessary.

• The larvae, not the eggs, are what often infect the host, and the common way is through the skin.

• The transmission of hookworm eggs is through human faeces that are contaminated.

• Within 48 hours, eggs in soil that is moist, warm, and well-oxygenated hatch into rhabditiform larvae.

• The rhabditiform larva undergoes two moults, on the third and fifth day, to change into a filariform larva, the parasite's infective stage. They have a life span of 2 weeks and are highly motile.

• Upon coming into touch with humans, the larvae enter through the foot, travel through blood vessels to the heart, and then to the lungs, where they are coughed up, consumed, and ultimately end up in the small intestine.

• In the small intestine, the larvae change into stage four, the adult worm.

• The adults that stay in the small intestine reach sexual maturity in 4-5 weeks.

• Adult hookworms live in the small intestine's lumen, where they stick to the walls and cause the host to lose blood as a result.

• When a female is fertilized, she starts to lay eggs, which are then passed into the environment through human waste. In one day, a female hookworm can lay up to 30,000 eggs.

• Thus, the cycle continues.

• It takes roughly five to nine weeks for the hookworm to mature within the intestine after the penetration from the soil.

Diagnosis of Hookworms

• The doctor will analyse faeces samples through a microscope to search for hookworm eggs.

• Doctors could advise blood tests to detect eosinophilia if the patient recently travelled to a region where hookworm is common.

• Chest X-Ray.

• In cases of hookworm infection, occult blood in the stool causes a severe reaction which is determined through an occult blood test.

Symptoms occur in infected humans even before diagnosis as it takes several weeks for the eggs to be seen in the faeces of an infected person.

Treatment of Hookworms

Depending on the type of hookworm and the affected host species, different types of treatments are available for hookworm infections, some of which can eradicate the infection with a single dose. To cure human worms, anthelmintic medications like albendazole and mebendazole are employed. Animals can be treated with a wide variety of anthelmintics. In severe cases of anaemia, replacement iron therapy, a highprotein diet, or a blood transfusion may be necessary.

Prevention

• In areas where the sand or dirt could be contaminated, you should either wear shoes or refrain from going barefoot.

• Avoid touching your skin to the ground in any way, including by sitting on it. Avoid drinking or eating anything that might be contaminated with soil.

• Defecating indoors is another way to avoid infection, as are efficient sewage disposal systems.

• Treatment for those who are infected

• Health instruction combined with better nutrition and dietary iron supplements.

Conclusion

The blood-sucking parasite hookworms reside in the small intestine of the mammalian hosts. The two most typical hookworm species that cause sickness are Necator americanus and Ancylostoma duodenale. Human faeces-contaminated soil is the major cause of hookworm infections in humans. It has a big impact on a person's lungs, skin, and small intestine. A prominent consequence of hookworms' nutritional depletion is severe chronic iron deficiency anaemia. Good hygienic practices plus proper treatment and a healthy environment can prevent infection from hookworm-like parasites.

FAQs

Q1. What are the common symptoms of hookworm infections in humans?

Ans. Not every hookworm patient will experience symptoms. Mostly they cause itching or a localised rash typically on the bottom of the foot. People with severe infection may experience: fatigue, diarrhoea, loss of weight, no appetite, anaemia, etc.

Q2. Are hookworms visible in human faeces?

Ans. They are invisible to the naked eye. However, the medical professional can examine the stool under a microscope to check for hookworm eggs.

Q3. Can hookworms that infect humans naturally disappear?

Ans. The natural disappearance of hookworms may take several years. This may result in severe health issues like starvation and anaemia in humans during that time which may be highly dangerous. Treatment and prevention is the best remedy for hookworm infections.

Q4. Does hookworm spread from pets to people?

Ans. Hookworm infections can occur in pets and when humans come in contact with the contaminated dirt with bare hands or feet, the hookworm eggs in the pet stool can enter into humans and cause illness.

Q5. How long do hookworms survive in the external environment?

Ans. Infectious larvae may live in the soil for several months or more under ideal circumstances, but in the tropics, the majority rarely do so for more than five to six weeks.